But the 46-year-old said she had resigned over a party policy which calls for Germany to intern all asylum-seekers in special camps.

Under the policy, asylum-seekers would be kept in “ethnically homogenous groups” and “prepared for their return to their country of origin”.

Mr Martin said the policy was reminiscent of the Madagascar Plan, a Nazi proposal in 1940 for the forced resettlement of Europe’s Jewish population on the island of Madagascar.

I originally joined the AfD because I wanted to criticise abusesClaudia Martin

The plan was never put into effect, in part because of a British naval blockade, but is seen as a crucial psychological step towards the Final Solution, which was adopted two years later.

“I originally joined the AfD because I wanted to criticise abuses. My concerns were about education and inclusion. I never discussed the issue of refugees,” Ms Martin told Frankfurter Allgemeine Zeitung newspaper.

“What I am experiencing now is that they take every opportunity to make a populist stand on the refugee issue, and they don’t try to draw any line against extremists.”

The AfD called for Ms Martin to resign her seat in the regional parliament, arguing she had only been elected as a party candidate.

The AfD’s success in Baden-Württemberg, one of western Germany’s richest states, was seen as evidence that the party could prosper outside its main strongholds in the impoverished states of the former communist east.

AfD federal chairwoman Frauke Petry Credit:
EPA

But the party has since been rocked by repeated controversy in the state. More than half its MPs in the regional parliament resigned the whip in protest and formed a rival party after the AfD refused to expel Wolfgang Gedeon, a member who had made comments supporting Holocaust denial. They were later persuaded to return to the AfD fold after Dr Gedeon resigned.